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I recently got a STi Ra DCCD swap.

I know the block is closed deck & is supposed to have forged pistons & hand ported heads, but does anyone know how strong the OEM forged pistons are?
Are the rods the same ones used in almost every Subaru motor (1.8, 2.0, 2.2) or are they upgraded?

I've heard these motors are strong, but how strong are they?

haha, oh man, you've got the cream of the crop right there! That DCCD is going to be amazing in an older legacy! Take a look at Splinter's thread. I'm pretty sure all RA engines were built very close to the same. The rods will probably be the wink link, like most high horsepower subaru's.

I'm going to leave the 4eat in the LSS, when it dies I'll get it rebuilt or upgraded internal parts for it from IPT which is located about 30 minutes from me.
The DCCD tranny is nice though & I may slap it into my Impreza when its tranny dies.

The Ra motor will either go in the Legacy as is, or its heads/5 injector intake will be put on a ej22t shortblock rebuilt with rods & pistons.

An EJ22G Ra would be amazing! That get's my vote. Future plans for mine are a full WRX crossover pipe, flipped intake, harness, and ECU swap. With ported heads, bored out to a 2.4 with forged everything, etc. Oh and a twinscroll Gt32r of course!

livestrong14 wrote:bored out to a 2.4 with forged everything, etc.

You mean stroked to a 2.4 right?

555BCTurbo wrote:

livestrong14 wrote:bored out to a 2.4 with forged everything, etc.

You mean stroked to a 2.4 right?

Okay I feel like an idiot and I am asking Nick for help.

JK

What is the difference? I know, stupid q but seriously what?

I asked Dave of Rallispec the specifics of the Ra motor & he said although they are probably the strongest factory shortblock & are still used as the base for WRC motors, the pistons are forged from a material that is a bit weaker than what is used in the aftermarket (to get tight clearances & cut down on noise) - limiting stock reliable output to 450hp.

He also said upgraded rods & pistons make 600-1000hp possible on the Ra (650hp being the limit of the stock crank), but if I'm going to buy rods & pistons I'd rather spend the $ on a motor with more displacement as he says the closed deck block casings are very similar on the Ra & ej22t with the Ra having better stock internals.

So EJ22 Ra here I come.

It will take a little while to get done, but I'm thinking ej22t shortblock with the STi Ra Heads/cams/intake as stated above.

Dave also mentioned that the rods were basically Impreza rods (forged like all the others) & that GD rods are stronger than GC rods due to them being a bolted cap design vs. the nut & bolt arrangement of the GC's.

I know folks were using STi rods in ej22ts which may be a good move if the above is correct & the ej22t shares the weaker GC design.

smh0101 wrote:
Okay I feel like an idiot and I am asking Nick for help.

JK

What is the difference? I know, stupid q but seriously what?

The difference between them is:

When an engine is bored, you are increasing the diameter of the bore...and subsequently must use larger pistons, which effectively increases the overall displacement of the engine...


When you stroke an engine, you take a crankshaft with longer throws, and therefore the piston travels farther, and creates more displacement that way. On a side note: Stroking also tends to increase torque markedly.

So the 2.35 stroker, which is an increasingly common engine build that people are doing consists of an EJ25 crank and rods, and a shorter decked piston built by Wiseco...which makes the EJ22T into an EJ235T

555BCTurbo wrote:

smh0101 wrote:
Okay I feel like an idiot and I am asking Nick for help.

JK

What is the difference? I know, stupid q but seriously what?

Yeah...maybe, just maybe, because Nick knows what he is talking about?

Occasionally...

But you are not infallible...

And thanks for answering my question... I wasnt really clear on that...

smh0101 wrote:

555BCTurbo wrote:

smh0101 wrote:
Okay I feel like an idiot and I am asking Nick for help.

JK

What is the difference? I know, stupid q but seriously what?

Yeah...maybe, just maybe, because Nick knows what he is talking about?

Occasionally...

But you are not infallible...

And thanks for answering my question... I wasnt really clear on that...

No one is infallible my friend...


except for Vikash...

555BCTurbo wrote:



except for Vikash...

Touché!

555BCTurbo wrote:When you stroke an engine, you take a crankshaft with longer throws, or longer connecting rods, or a combination of both, and therefore the piston travels farther, and creates more displacement that way. On a side note: Stroking also tends to increase torque markedly.

Increasing stroke is only accomplished w/ longer crank throws. Longer rods simply raise the piston in the bore.

and for a given deck height when you stroke you use shorter rods.

206er wrote:and for a given deck height when you stroke you use shorter rods.

Good point...I have no idear what I were thinking...damn beer is making me dumb!

....and after a comment like that, the Psychostick "Beer song" plays in my head.

(If you've never heard it, go to myspace or youtube and look it up. You'll definitely enjoy it!)

Nick wrote <<<So the 2.35 stroker, which is an increasingly common engine build that people are doing consists of an EJ25 crank and rods, and a shorter decked piston built by Wiseco...which makes the EJ22T into an EJ235T >>>

I want this!!!

BXSS wrote:Dave also mentioned that the rods were basically Impreza rods (forged like all the others) & that GD rods are stronger than GC rods due to them being a bolted cap design vs. the nut & bolt arrangement of the GC's.

I know folks were using STi rods in ej22ts which may be a good move if the above is correct & the ej22t shares the weaker GC design.

The STi rods are a direct match for the EJ22T rods in both length (130.5mm) and journals (52mm big end, 23mm small end). And not only do the Sti rods have the pinned cap and bolt design but they also have a notably larger beam section. They are no doubt the strongest factory rod.

Note: the STi rods are the wrong length and big end journal size for the standard 2.35 stroker build using the EJ25 phase I crank and rods. Check this post for more rod info: http://bbs.legacycentral.org/viewtopic.php?t=33735

Gary

P.S. I am currently building a 2.35 stroker with the STi crank and rods (block will be machined for phase II crank).

back on track, I have gotten ahold of the same and the STI RA come with some impressive stock numbers, 275 horse and around 260 tq with the tdo5. Mines going as is into my 92 with a spider dccd controler.

Yeah it does make decent power stock, but I think part of the reason is that the ECU has a high boost target (maybe possible because of the forged pistons ?).

I lucked out & got the DCCD controller, wiring, selector switch, & 3.9 2way Mechanical LSD/axles with my swap.

BXSS wrote:Yeah it does make decent power stock, but I think part of the reason is that the ECU has a high boost target (maybe possible because of the forged pistons ?).

I lucked out & got the DCCD controller, wiring, selector switch, & 3.9 2way Mechanical LSD/axles with my swap.

So the DCCD controller on the old boxes is separate from the ECU then?!?

It is a little black box that gets plugged into the selector switch-wheel & something else - I have to look @ the rest of the harness to see what goes where.

ECU is the same 4 plug ECU as any 20G on the outside, with more aggressive mapping inside.

the DCCD controler connects to the diff and the tumbwheel. it also has wires to the ebreak somewhere in there. I didnt get the controller or the thumbwheel, but spiders manual unit is only a couple hun, and the autos only just over 3 hun and does some cool stuff!

mine also came with a zerosports tuned ECU so i dont even know what its capable of. Going to run it with a better (vf22) turbo and a big FMIC and eventualy dyno it.

anyone ever try and lock the diff and pull front ales to do a rwd dyno pull? only reason is theres a reasonably priced dyno in town here but only 2wd. otherwise I am going to Rocket in squamish or somewhere in Calgary, both out of my way.

PS thats pretty sweet to get the mechanical LSD for the tranny, I happen to have a 3.9 r180 rear diff to put in mine, otherwise its 91 tleg that I have.

Funny you mentioned connecting to the e-brake, as my '99 OBS has a loose plug in the ebrake area that fits into the open slot of the DCCD controller.
So newer Imprezas may have some of the DCCD wiring in place...?....

I would not risk damaging the tranny (center diff) to 2wd dyno the car, though you probably could get away with doing that (pulling th e-brake up).

I'd assume the Zero sports computer must make some HP over the stock STi Ra ECU (which EJ20G folks pay $$$ for).